I guess there would have to be some sort of mechanism to put in provisional moves and an option to pull them back. So you'd want to allow combat movement to be entered provisionally assuming everyone is at war I suppose then re-validated to check they're still desired once the other player has finished their turn. Perhaps something similar for the buy too but that's the smaller part. Even smaller is the politics.

@schulz You could already achieve this after a fact. In that you can make all the nations on either side of a conflict move in a synchronized manner. The main issue is that due to the way this needs to be set up it means that ...

Each side of a conflict would have its own turn. (Individual nations would not move independently)
The game would essentially have be a 2 player game. (1 player has to control all of one side)
The XML construction becomes quite daunting.

The other thing to remember is that depending on how large the map is, and how many factions are within each side of the conflict... setting this up this way tends to create a massive set of moves for each player.

It is so interesting but probably require complicated works. Can you give me at least one example XML if possible? Or I can make it as testing on the simpliest triplea map if you are able to tech the method to me.

@schulz Now I will forewarn you that trying to do this on such a game level scale becomes very challenging if you want to do it properly.

Just a couple of things you need to bear in mind before you try this...

All territories on the map have to be assigned who will take possession of the territory when it is captured. This is still fraught with challenges as these predetermined settings are fixed.

Unless you want all units to become a homogenized unit when they convert into the controlling Major... it means that every unit of each Minor has to be duplicated in the unit roster of the associate major. So in the Major Allies unit roster you would end up with: Allied British Infantry, Allied American Infantry, Allied Russian Infantry, Allied British Artillery, Allied American Artillery, Allied Russian Infantry... etc etc etc down through every unit in each nations roster.

There are even more complexities as you work through this concept, but probably best that you simply ask as you discover them.

@schulz To my knowledge TWW is the only map that uses this system. That is not to say it couldn't be done in any map. Just someone needs to have the intestinal fortitude to actually do it. Or make it worth my while to do it for them.

@schulz For those that don't know the game, can you clarify if by simultaneous turn you mean all the powers of the same side moving/attacking together or everyone (both the attacker and the defender) moving/attacking at the same time (like planning the movements in secret, revealing them, and doing them)?

I guess there would have to be some sort of mechanism to put in provisional moves and an option to pull them back. So you'd want to allow combat movement to be entered provisionally assuming everyone is at war I suppose then re-validated to check they're still desired once the other player has finished their turn. Perhaps something similar for the buy too but that's the smaller part. Even smaller is the politics.

Assuming you mean for all the players at the same time, not just the ones of a same side, to avoid a potential infinite loop of readjustments, simply keep the moves stored in the gamer's terminals, then once both have finalized them, the terminals send them to the hosting terminal, and the turn gets done. Like if you would keep two boards in two separate rooms. Tho if he here only means being able of making D-Day together (as @Hepps understood), we are off topic.

For example in a wwii map; Axis and Allies players will be able to move all units but neither of side will be able to see their opponen's movements until battles occur after the movement stage. Let assume 3 Italian armours decide to attack to 2 British infantry in Egypt. During the movemen phrase; Allies player can predict Italy is going to attact Egypt with 3 armours. Allies player can pull back 2 british inf to Trans-Jordan. In this case no battle is occur. Italy takes Egypt with 3 armours. If 2 British inf stay, battle occurs British infantries are count as 2 defenders (with their 2 defense power).

But if 3 Italian armours move Egypt from Lybia and 2 British Infantry move Lybia from Egypt in the same round then the battle should be occur like this;

Italian Armours perform the same because armour's attack and defense powers are equal. They are count as attacker and British infantries are count also attacker too. British infantryes' attack power is 1.

Also in sumultaneous rounds system multiple countries can attack enemies together. In the system you will have to predict your opponents movements before to move your units. It works well only in big maps.

@schulz Ok, then I can assure you that this is not possible (and @Hepps didn't guess correctly what you wanted), but good idea (for a developer).

Actually, if you play Axis&Allies, you can house rule something like this, if you keep two boards in two rooms. As far as realism is concerned, probably the map would need to have territories at most a few hundreds km wide, like NWO or more parceled.

I think war room (the upcoming game from Larry Harris) has simultaneous actions on both sides. That won't be possible to implement in Triple-A as we know it.

If you're talking about having a game with simultaneous actions then that would break every game within Triple-A or, if it were optional, have no games within Triple-A. I don't think such a proposition can be considered.